The present invention relates to shift devices, and, more particularly, to shift devices for automatic transmissions of vehicles.
Generally, an automatic transmission of a vehicle is connected to a shift device. The shift device includes a lever manipulated by a driver to shift the transmission.
FIGS. 1 to 3 show a prior art shift device 71. The shift device 71 includes a shift lever 74 (see FIG. 2), which is manipulated by a driver, a base 72, and a housing 73. The base 72 is secured to a vehicle body and the housing 73 accommodates a lower portion of the lever 74.
As shown in FIGS. 1 and 3, the housing 73 is secured to the base 72 with a bolt 75 and a nut 76. A pair of bearing pieces 77a, 77b project downward from the bottom of the base 72. The bearing pieces 77a, 77b include shaft holes 78a, 78b, respectively. The shaft holes 78a, 78b support a shaft 80. A C-ring 79 is fitted around the distal end of the shaft 80.
As shown in FIGS. 2 and 3, the shaft 80 rotationally supports a sleeve 81. The sleeve 81 includes a cable connector 81a that projects upward from the sleeve 81. The cable connector 81a has a cylindrical projection, which is parallel with the axis of the sleeve 81. The projection rotationally supports a wire 82a of a control cable 82. Movement of the shift lever 74 is transmitted to an automatic transmission (not shown) through the wire 82a. The sleeve 81 includes a pin connector 81b that projects downward from the sleeve 81. The pin connector 81b has a pin hole 81c, which is perpendicular to the axis of the sleeve 81.
The pin hole 81c rotationally supports a rotary shaft 84. A C-ring 83 is fitted around the distal end of the rotary shaft 84. The shift lever 74 has a yoke at its base, which includes a pair of yoke members. One yoke member is located between the pin connector 81b and the proximal end of the rotary shaft 84, and the other is located between the pin connector 81b and the C-ring 83. This structure enables the shift lever 74 to pivot with respect to the rotary shaft 84 and the shaft 80.
The shift lever 74 includes a shift rod 74a. A shift knob is attached to the distal end of the shift rod 74a. A distal portion of the shift rod 74a projects upward from the housing 73 through a guide groove 85.
As shown in FIG. 1, the guide groove 85 is formed in an upper wall of the housing 73. The guide groove 85 guides movement of the shift rod 74a. 
A positioner 73a is formed along an inner wall of the housing 73. The positioner 73a includes a plurality of convex and concave portions that alternate with one another. The positioner 73a is located at one side of the guide groove 85.
The shift lever 74 has a movable pin holder 86 for holding a movable pin 88 and a spring 87. The spring 87 urges the movable pin 88 toward the positioner 73a such that the distal end of the movable pin 88 abuts against the positioner 73a. If the shift lever 74 is manipulated, the movable pin 88 moves along the positioner 73a in accordance with the shape of the positioner 73a. The movable pin 88 and the positioner 73a form a first positioning mechanism for positioning the shift lever 74 in a fore-and-aft direction of the vehicle.
A second positioner 90 and a second movable pin (not shown) laterally position the shift lever 74. The second positioner 90 is located separate from the first positioner 73a. 
A cable holder 89 is formed at the front end of the base 72 to hold the control cable 82.
In the shift device 71, the housing 73 and the base 72 are formed separately in independent molds. Further, the shift lever 74 is formed separately from the sleeve 81. Also, in addition to the sleeve 81 that connects the shift lever 74 to the shaft 80, the shift device 71 employs the C-ring 79 to prevent the shaft 80 from escaping from the bearing pieces 77a, 77b. In other words, a relatively large number of components support the shift lever 74. This complicates the manufacturing process of the shift device 71 and increases the manufacturing costs.
Japanese Unexamined Patent Publication No. 8-334167 describes a shift device that has an electric device such as a shift locking solenoid. The solenoid is mounted on the base. Thus, if liquid enters the interior of the shift device, the electric device is exposed to the liquid, which can damage the electric device.
Accordingly, it is a first objective of the present invention to provide an inexpensive shift device with fewer parts.
It is a second objective of the present invention to provide a shift device that protects an electric device installed in the shift device from liquid.
To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, the invention provides a shift device for shifting an automatic transmission of a vehicle. The shift device includes a shift lever and a case. The shift lever is moved among a plurality of shift positions. The case receives a lower portion of the shift lever. The case includes a housing and a base. The housing accommodates the lower portion of the shift lever and has a guide hole that guides the movement of the shift lever. The base is formed integrally with the housing and is attached to the vehicle.
A further perspective of the present invention is a shift device for shifting an automatic transmission of a vehicle. The shift device includes a shift lever, a cable connector, a case, and a positioning mechanism. The shift lever is moved among a plurality of shift positions. The cable connector is connected to a control cable that transmits the movement of the control cable to the automatic transmission. The cable connector is formed integrally with the shift lever. The case receives a proximal portion of the shift lever and the cable connector. The positioning mechanism permits the shift lever to be manipulated accurately. The positioning mechanism includes a positioning surface located in the case and a positioning component located in the shift lever. The positioning surface includes a plurality of concave portions. The positioning component is pressed against the positioning surface.
A further perspective of the present invention is a base for a shift device with an electric component. The base is secured to a vehicle body. The base includes an accommodating portion. The accommodating portion is formed integrally with the base for accommodating the electric component. The accommodating portion includes a top plate that covers at least an upper portion of the electric component. The electric component is secured to the top plate.
A further perspective of the present invention is a support structure for rotationally supporting a shift lever that shifts an automatic transmission of a vehicle. A case receives a proximal portion of the shift lever. The support structure includes a support shaft, an engagement piece, and first and second bearing pieces. The support shaft has a distal end and a proximal end and is connected to a proximal end of the shift lever. The engagement piece is formed integrally with the support shaft and projects radially from the support shaft. The first and second bearing pieces are located in the case and rotationally support the support shaft. At least one bearing piece has a slit for accommodating the engagement piece and an attachment hole connected to the slit. A step is formed between the slit and the attachment hole. The engagement piece moves in the slit when the support shaft rotates around the axis of the support shaft. The support shaft becomes inseparable from the first and second bearing pieces through the attachment hole when the engagement piece engages with the step at a predetermined engagement position in the slit. The support shaft becomes separable from the first and second bearing pieces through the attachment hole when the engagement piece is located at a position other than the engagement position in the slit.
A further perspective of the present invention is a shift device for shifting an automatic transmission of a vehicle. The shift device includes a shift lever, a cable connector, a case, and a positioning mechanism. The shift lever is moved among a plurality of shift positions. The cable connector is formed integrally with the shift lever and is connected to a control cable that transmits the movement of the shift lever to the automatic transmission. The case receives a proximal portion of the shift lever and the cable connector. The case includes a housing and a base. The housing accommodates a portion of the shift lever and has a guide hole that guides the movement of the shift lever. The base is formed integrally with the housing and is attached to the vehicle. The positioning mechanism enables the shift lever to be manipulated accurately. The positioning mechanism includes a positioning surface located in the case and a positioning component located in the shift lever. The positioning surface has a plurality of concave portions for positioning the shift lever. The positioning component is pressed against the positioning surface.